:root {
  --primary: #1E3A8A;
  --secondary: #10B981;
  --accent: #F59E0B;
  --bg: #F3F4F6;
  --text: #111827;
  --white: #ffffff;
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:Inter,Roboto,Arial,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}
.site-header{background:var(--primary);color:var(--white);padding:14px 28px;position:fixed;top:0;width:100%;z-index:100}
.nav{display:flex;justify-content:space-between;align-items:center}
.nav-links{list-style:none;display:flex;gap:18px}
.nav a{color:var(--white);text-decoration:none;font-weight:600}
.nav a:hover{color:var(--accent)}
.main{padding-top:78px;max-width:1100px;margin:0 auto;padding-left:20px;padding-right:20px}

/* Hero */
.hero{text-align:center;padding:100px 20px 40px}
.hero h1{font-size:2.4rem;color:var(--primary);margin-bottom:10px}
.hero p{font-size:1.05rem;margin-bottom:18px}

/* Cards grid */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px}
.card{background:var(--white);padding:20px;border-radius:12px;box-shadow:0 6px 20px rgba(0,0,0,0.06)}
.card h3{color:var(--primary);margin-bottom:8px}

/* Profile */
.profile-card{max-width:720px;margin:60px auto;padding:28px;background:var(--white);border-radius:12px;box-shadow:0 8px 30px rgba(0,0,0,0.08);text-align:center}
.avatar{width:110px;height:110px;border-radius:50%;object-fit:cover;margin-bottom:12px}
.profile-card h2{color:var(--primary);margin-bottom:6px}
.profile-card p{margin:6px 0}

/* Progress */
.progress-container{width:100%;background:#e9e9e9;border-radius:12px;height:18px;margin-top:10px;overflow:hidden}
.progress-bar{height:100%;background:var(--primary);transition:width .6s ease;border-radius:12px}
.progress-bar.full{background:var(--secondary)}

/* Leaderboard */
.leaderboard table{width:100%;border-collapse:collapse;background:var(--white);border-radius:8px;overflow:hidden}
.leaderboard th, .leaderboard td{padding:12px;border-bottom:1px solid #eee;text-align:left}
.top1{background:#FFD700}
.top2{background:#C0C0C0}
.top3{background:#CD7F32}

/* Messages */
.msg-list{list-style:none}
.msg-list li{background:var(--white);padding:14px;border-radius:8px;margin-bottom:10px;box-shadow:0 4px 12px rgba(0,0,0,0.04)}
.msg-list strong{color:var(--primary)}
.msg-list .time{float:right;color:#666;font-size:.9rem}

/* Admin */
.admin table{width:100%;border-collapse:collapse;background:var(--white);margin-bottom:20px}
.admin th, .admin td{padding:12px;border-bottom:1px solid #eee}

/* Auth */
.auth-container{display:flex;justify-content:center;align-items:center;min-height:80vh;padding-top:40px}
.auth-card{background:var(--white);padding:36px;border-radius:12px;box-shadow:0 10px 30px rgba(0,0,0,0.08);width:100%;max-width:420px}
.auth-card h2{color:var(--primary);margin-bottom:14px}
.auth-card label{display:block;margin:10px 0 6px;font-weight:600}
.auth-card input{width:100%;padding:10px;border:1px solid #ddd;border-radius:8px;margin-bottom:12px}
.btn, .btn-primary{background:var(--primary);color:var(--white);padding:10px 14px;border-radius:8px;border:none;cursor:pointer;text-decoration:none;display:inline-block}
.btn:hover, .btn-primary:hover{background:var(--secondary)}
.btn-success{background:var(--secondary);color:#fff;padding:8px 12px;border-radius:8px;border:none}

/* Footer */
.site-footer{background:var(--white);border-top:1px solid #e6e6e6;padding:22px 28px;margin-top:40px}
.footer-inner{display:flex;flex-wrap:wrap;justify-content:space-between;gap:12px;align-items:center}
.footer-links a{margin:0 8px;color:var(--primary);text-decoration:none}
.footer-bottom{margin-top:12px;text-align:center;color:#666}

/* Responsive */
@media (max-width:720px){
  .nav-links{display:none}
  .hero h1{font-size:1.8rem}
  .profile-card{margin:90px 12px}
}